Finishing up a Kerdi shower questions

I'm finally finishing a bathroom remodel and would like a little finishing advice from the experts here.

It has a Kerdi shower with glazed ceramic tiles. One wall is tempered glass sitting on a tile/Kerdi curb on clear setting blocks and tiled around with glazed soft-body tiles. I have not caulked around the glass yet. Because this is a wet wall I would like to avoid mold/mildew and was considering using Lexel instead of silicone.

1) Is Lexel compatible with Kerdi? I don't want it to melt!

2) I've used white thinset and the orange Kerdi is mostly covered with white but there is still a little orange showing through in a few spots. If I use clear Lexel will this be very noticeable? Because the glass is already surrounded by tile it would be difficult to paint it at this point. The tile is grouted with bright white grout. Maybe I should use white Lexel?

3) I've read Lexel is difficult to tool. Does it flow very well? Would warming the tube help? Because the bottom of the tempered glass is enclosed by level tile and grout, the ideal sealant would flow well and I could pool it around the glass.

I don't want to screw up un this finishing stage so any and all advice/tips are very welcome.

1. Don't know, but you probably have a scrap of Kerdi around, you could try (assumes you already have some). Kerdi is polyethelene, the tube should list any precautions regarding materials, and, Schluter has a pretty good tech support group - free call, Monday's only hours away, give it a try.
2. Not great, without close to 100% coverage, it could be an issue.
3. See 1.

Thanks but you guys are great here. More often then not there is no one willing or able to answer my questions as they arise at the JB forum. Since the project must keep moving forward I often have to just take my best guess at the next step without the assistance of those who have been there, done that.

I just called Schulter tech support and spoke to a real rep without going through pre-recorded menus, etc. Very refreshing. He grasped my question on compatibility right off, said that was a good question and that he would fire off an e-mail to the appropriate technical expert and call me back. Nice. Lexel says to test for compatibility on specific products but I don't have 10 years to wait to see if it slowly degrades the Kerdi or not.

My experience with Schluter has been good...good products, good support.

In contrast, I left a question on Custom's help section on their website, and it's been two months...no call, no e-mail, no response. Not very friendly or helpful at all. I hope this is the exception, but I do not know.

Nice! Schluter rep already called back with a definitive answer. No! Lexel is not compatible with Kerdi (because it's made of polypropylene). He did suggest that Schluter offers an aluminum channel to fit tempered glass that would have achieved the look I wanted and allowed the bedding of glass in Lexel but I was not aware of this when I got the idea to set the glass directly on bedding blocks when I was reading up on this during the planning stage.

So it's either a silicone caulk or a urethane based caulk. Anyone know the disadvantages/advantages of urethane vs. silicone?

Schluter has a really neat visualization tool on their website called Schluter House. At least for now, they burry it in the lower right-hand corner of their home page, but I really think it should be higher...many people never scroll down that far to find it.

Some of the stuff they show needs to be updated to showcase their latest products, but most of it is up to date. It can also show you the abbreviated how-to and produce a materials list. You can select various tile choices and sizes along the way and get a reasonable idea of how things would look, and then how to do it. Check it out when you get a chance http://www.schluterhouse.com/.

Nice! Schluter rep already called back with a definitive answer. No! Lexel is not compatible with Kerdi (because it's made of polypropylene). He did suggest that Schluter offers an aluminum channel to fit tempered glass that would have achieved the look I wanted and allowed the bedding of glass in Lexel but I was not aware of this when I got the idea to set the glass directly on bedding blocks when I was reading up on this during the planning stage.

So it's either a silicone caulk or a urethane based caulk. Anyone know the disadvantages/advantages of urethane vs. silicone?

Click to expand...

Mike , the links provided for the silicone to be used in your application are the right choice . The latasil or the mapesil are designed to handle the task at hand with great success -- Quote : '' this is a wet wall I would like to avoid mold/mildew.'' -- ..... Not only they are available in different colors if desired , but are easy to use and with masking tape and patience they do a perfect job . I should also say that silicone can be applied in narrow joints -- 1/8 -- if necessary , without air pockets .

Now , for the polyurethane , pretty much the opposite of the above . Not for your application.

One question comes to my mind ......is the Kerdi visible through the glass panel ?

One question comes to my mind ......is the Kerdi visible through the glass panel ?

Click to expand...

Thanks for the specifics Roberto.

I can't see the Kerdi through the glass panel probably because the edge of the pane is raised off the Kerdi by 1/8" setting blocks. If I use a clear silicone to fill the channel that might change, no? Personally, I think a little orange color showing might be aesthetically pleasing with my color scheme but only if it was a diffuse glow of color in places, not if it were like looking through a window or magnifying glass at a sloppy construction detail. See what I mean? And since I have no experience with clear silicone in anything but a regular corner bead, I'm not sure what the likely effect would be.

The glass is 3/8" tempered rain glass, smooth on the shower side and not really visible on the rain texture side (beside a laundry pair). When I look down at the base of the pane from inside the shower the glass actually appears to have a pleasant aqua blue color although it is basically clear glass. I can also see white thinset in the u-channel where it was burned into the Kerdi and a few spots where a bit of orange shows through. I can't currently see any of that reflected in the glass, only direct in the bottom of the channel. The white tiles are all cut where they create the channel and they are typical reddish-brown ceramic on the inside with white grout joints terminating at the edge of the channel.

I guess my question is how diffuse these construction details will appear through clear silicone?

Clear silicone is pretty vague for me , Mike . Not all of them give the same effect ...some are more see trough than others . You can also get a translucent one if you like the see through look .

Only if you purchase and do some local tests with them , you will probably find the right one for your application . Don't ask me how I know ....just having around 50 tubes of different mfgs and colors makes the choice harder , not simpler . You know how it is when looking for the perfect one , right ?

Do you have any pics of the area(s) where the silicone will be applied ?

Clear silicone is pretty vague for me , Mike . Not all of them give the same effect ...some are more see trough than others . You can also get a translucent one if you like the see through look .

Only if you purchase and do some local tests with them , you will probably find the right one for your application . Don't ask me how I know ....just having around 50 tubes of different mfgs and colors makes the choice harder , not simpler . You know how it is when looking for the perfect one , right ?

Click to expand...

Looks like I came to the right spot, lol!

I took some pictures at the job site recently that I think will show what you need. I'll see if I can dig them up and figure out how to post them (every forum seems to have different requirements).

Here is an example of the effect -- black epoxy grout on the black floor tiles -- with the glass panels . Originally the glass installers applied a clear silicone . The client didn't like the look of a not matching color -- clear silicone -- in between the glass and the tiles .......the black was the winner.

Same was applied on the walls -- matching color of the grout -- in between the glass and the wall tiles .

Better if you ask these with a follow up post , instead of editing the post ? Hard to follow up what changed in the questions .

Click to expand...

Sorry about that. I was using a touchscreen to post my question and it sent before I had finished the post. Dang touchscreens!

Pics ? Let's see the area in question, maybe a different color will work . White ...... for example .

Click to expand...

White will work and maybe is the best option. I am concerned about getting a good line on the backside of the heavily textured 'rain' glass, which is why I was leaning towards clear. I am planning on using a white sanded caulk for the tiled changes of plane but am unsure if this is the best choice to bed the glass pane in.

Let's see if I can make these pics work:

Overview

Back right corner

Outside Curb
Here you can see the glass pane is not centered for these photos (I moved it over to make a little more room for tiling the outside of the curb).

Back wall

Ceiling

The glass disappears into an extruded aluminum channel at the top which is covered with an "L" shaped stainless steel decorative cover, one inside, one outside (some of it still covered with the protective vinyl). The glass company said I could use clear silicone to affix it to this channel inside and out but I might be in over my head on this one. If I recall there is an 1/8" gap on either side of the pane but the extruded aluminum edge I need to caulk to is not very substantial (doesn't provide a large caulking surface).

I would use clear silicone in between the SS and glass . Before doing it , make a few spots just 1/16 deeper than the front face of the SS trim , let them cure for 24h and then get rid of the wood spacers . If you have clear , soft and the right thickness plastic shims -- instead of doing the silicone spots -- you can insert them to replace the wood spacers . Use masking tape to protect each side of the joint while applying the silicone . Tool it flat while forcing it into the joint and remove the excess until is flat and nice looking , leaving as little as possible of silicone residue on the masking tape near the joint . Remove the masking tape and you should be done . If you prefer to practice before doing it , make a sample set up with 2 tiles as per your application .

For the rest -- tile to glass joint and tile to SS -- , I would suggest you to do the silicone -- before grouting --the same color as your grout color for the tiles .
Using an epoxy grout like Spectralock -- it will work great for your application -- from Laticrete may also be beneficial -- white or light colors -- .No sealer needed , non staining and just benefits . Latasil comes in white color so you should be fine .

Sanded white caulk is probably siliconised acrylic and is not as resistant as 100% silicone for a shower application .

I wouldn't worry much about the textured face of the glass panel . Masking tape the glass as good as possible -- leave around 1/32 higher -- and take your time .

Use masking tape to protect each side of the joint while applying the silicone . Tool it flat while forcing it into the joint and remove the excess until is flat and nice looking , leaving as little as possible of silicone residue on the masking tape near the joint . Remove the masking tape and you should be done . If you prefer to practice before doing it , make a sample set up with 2 tiles as per your application .

Click to expand...

OK, the overhead joint will be the only clear on the job. I'm not very good at caulking but somehow, over the years, my wife has come to believe I'm a caulking God. But that impression is from simple, small corner beads without masking, not overhead gaps between glass and metal! I will try to apply it as evenly as possible but I'll be working with a large hole in the end of the tube and some areas are bound to have more caulk behind. I'm thinking it might sag unevenly after tooling due to the weight of the caulk above various sections of the joint.

1) Do some clear silicones have a more stiff consistency/less sag out of the tube? Would you refrigerate the tube of silicone before using? Recommendations on clear silicone for this application? I'll be placing an order via Internet so availability is not a concern.

For the rest -- tile to glass joint and tile to SS -- , I would suggest you to do the silicone -- before grouting --the same color as your grout color for the tiles .
Using an epoxy grout like Spectralock -- it will work great for your application -- from Laticrete may also be beneficial -- white or light colors -- .No sealer needed , non staining and just benefits . Latasil comes in white color so you should be fine .

Click to expand...

I'm still open to epoxy or urethane grout although I have done a test board with CBP Polyblend cement grout in brilliant white and was so pleased with the result I've grouted the outside left side of the curb with it (but there's no reason I can't switch for the wet areas).

2)Did you bring up epoxy grout at this point due to color consistency to match the silicone caulk or other considerations? I'm aware of the many advantages but I think in terms of color match I am very easy to please and bright white is a relatively easy color to match.

The shower floor is grouted with Bostik Urethane Dimensions grout and I think it made it easy to fill the deep and narrow grout lines in the stone mosaic floor without leaving voids and it resulted in a superior, slightly flexible monolithic result but it was stressful cleaning it up as it began to dry on the surface. Not sure I want that kind of stress. I still need to clean up the surface a bit better.

I'm interested in the order or grouting/caulking. On the JB forum I saw a preference for grouting first/caulking second but, when I asked for details I was met with silence which is the typical response (lack of) so I've just about given up wasting my time. But on the small portion I've done so far I've grouted first, caulked second which is maybe not ideal.

I wouldn't worry much about the textured face of the glass panel . Masking tape the glass as good as possible -- leave around 1/32 higher -- and take your time .

Click to expand...

I don't have a spare piece of rain glass to practice with.

3) When I tape I assume I should push the tape into the indentations in the glass texture. The problem I'm trying to anticipate is that I don't think I can tool all of the white caulk out of the indentations and when I pull the tape it will pull the remaining caulk and leave a 'torn' or ragged edge? How soon do I need to pull the tape after tooling (before it begins to skin)? Maybe for the textured side of glass at the bottom I should switch to clear silicone so any messiness doesn't show through to the inside of the shower? Other recommendations? What about applying the caulk bead without masking and then misting it with the tooling/no-stick agent before smoothing the bead with my finger or a tool misted with the tooling agent?

Sanded white caulk is probably siliconised acrylic and is not as resistant as 100% silicone for a shower application .

Click to expand...

I have used sanded white (siliconised) on dry areas outside the shower but I was under the impression that the companies you mentioned above offered sanded silicone caulk. I need to place an order but am completely undecided on brands because I have so little to go on. My priorities look like this:

Plan a weepage drain on the curb tiles (something like fishing line or candle wick)

Infill the gap with white silicone and rake it back tight.

Leave it for four days.

Hit it again with Translucent (not clear) silicone.

What a day or two.

Christin that bad boy! LOL

Click to expand...

John, I like the idea of weep holes and have seen you describe them on other threads. But your descriptions have never allowed me to understand the details of their construction. Call me dense but I can't say I haven't read and re-read, pondered and tried to understand. Is fishing line hollow? Is the fishing line bedded in grout and pulled out before the grout fully cures? Is the candle wick left in place?

Love the idea but still mystified on the details.

I would love to see a concise but detailed description of a weepage drain. I assume they run between the curb tiles in this instance but that's all I can gather.

Siliconized acrylic is the easiest one to work with . It is washing like the regular grout . You may have to do it twice , if sagging takes place .
However you need the strength of a 100% silicone or RTV to hold the glass panel .
Also , in a shower environment , in the long run I would not recommend the SA -- siliconized acrylic --.

I suggested you the epoxy grout , for worries free , especially if bright white is the color you are looking for . Worries free means , no color changes when exposed to water , no sealing needed , easy maintenance , etc. It is really your choice .

Urethane grout ....I really hope you didn't over wash it . I am not a fun of it in the showers , but if the 7 to 10 days cure is respected without the exposure to direct water , will work just fine.

To apply the RTV or 100% silicone , I use ALL the time masking tape and I am tooling it , to get the uniformity , the right depth -- pushing it in -- , clean edges and no waiveness. Without it , sometimes it works good , sometimes it is a disaster .